Alarm characterization for analyte monitoring devices and systems

ABSTRACT

Methods and apparatus including determining a rate of occurrence of a glycemic excursion event, determining a frequency of an alarm activation associated with the glycemic excursion event, determining an analyte level associated with the alarm activation, and setting an alarm parameter based on one or more of the determined rate of occurrence of the glycemic excursion event, the frequency of the alarm activation associated with the glycemic excursion event or the determined analyte level are provided.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/675,643, filed Aug. 11, 2017, which is a continuation of U.S.application Ser. No. 14/997,463 filed Jan. 15, 2016, now U.S. Pat. No.9,730,650, which is a continuation of U.S. application Ser. No.12/616,129 filed Nov. 10, 2009, now U.S. Pat. No. 9,326,707, whichclaims priority under 35 U.S.C. § 119(e) to U.S. Provisional ApplicationNo. 61/113,211 filed Nov. 10, 2008, entitled “Alarm Characterization foran Adjunctive Continuous Glucose Monitoring Device”, the disclosures ofeach of which are incorporated herein by reference for all purposes.

BACKGROUND

The detection of the level of analytes, such as glucose, lactate,oxygen, and the like, in certain individuals is vitally important totheir health. For example, the monitoring of glucose is particularlyimportant to individuals with diabetes. Diabetics may need to monitorglucose levels to determine when insulin is needed to reduce glucoselevels in their bodies or when additional glucose is needed to raise thelevel of glucose in their bodies.

SUMMARY

Embodiments of the present disclosure include determining a rate ofoccurrence of a glycemic excursion event, determining a frequency of analarm activation associated with the glycemic excursion event,determining an analyte level associated with the alarm activation, andsetting an alarm parameter based on one or more of the determined rateof occurrence of the glycemic excursion event, the frequency of thealarm activation associated with the glycemic excursion event or thedetermined analyte level.

In a further aspect, there is provided an interface component, one ormore processors operatively coupled to the interface component, and amemory for storing instructions which, when executed by the one or moreprocessors, causes the one or more processors to determine a rate ofoccurrence of a glycemic excursion event, determine a frequency of analarm activation associated with the glycemic excursion event, determinean analyte level associated with the alarm activation, and set an alarmparameter based on one or more of the determined rate of occurrence ofthe glycemic excursion event, the frequency of the alarm activationassociated with the glycemic excursion event or the determined analytelevel.

These and other features, objects and advantages of the presentdisclosure will become apparent to those persons skilled in the art uponreading the details of the present disclosure as more fully describedbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of an embodiment of a data monitoring andmanagement system according to the present disclosure;

FIG. 2 shows a block diagram of an embodiment of the transmitter unit ofthe data monitoring and management system of FIG. 1;

FIG. 3 shows a block diagram of an embodiment of the receiver/monitorunit of the data monitoring and management system of FIG. 1;

FIG. 4 shows a schematic diagram of an embodiment of an analyte sensoraccording to the present disclosure;

FIGS. 5A-5B illustrate a perspective view and a cross sectional view,respectively of another embodiment of an analyte sensor;

FIG. 6 is a flowchart illustrating a routine for establishing or settingan alarm parameter based on glycemic excursion events in accordance withone embodiment of the present disclosure; and

FIG. 7 is a flowchart illustrating a routine for determining a rate ofoccurrence of a glycemic excursion event in accordance with oneembodiment of the present disclosure.

INCORPORATION BY REFERENCE

The following patents, applications and/or publications are incorporatedherein by reference for all purposes: U.S. Pat. Nos. 4,545,382;4,711,245; 5,262,035; 5,262,305; 5,264,104; 5,320,715; 5,509,410;5,543,326; 5,593,852; 5,601,435; 5,628,890; 5,820,551; 5,822,715;5,899,855; 5,918,603; 6,071,391; 6,103,033; 6,120,676; 6,121,009;6,134,461; 6,143,164; 6,144,837; 6,161,095; 6,175,752; 6,270,455;6,284,478; 6,299,757; 6,338,790; 6,377,894; 6,461,496; 6,503,381;6,514,460; 6,514,718; 6,540,891; 6,560,471; 6,579,690; 6,591,125;6,592,745; 6,600,997; 6,605,200; 6,605,201; 6,616,819; 6,618,934;6,650,471; 6,654,625; 6,676,816; 6,676,819; 6,730,200; 6,736,957;6,746,582; 6,749,740; 6,764,581; 6,773,671; 6,881,551; 6,893,545;6,932,892; 6,932,894; 6,942,518; 7,167,818; and 7,299,082; U.S.Published Application Nos. 2004/0186365, now U.S. Pat. No. 7,811,231;2005/0182306, now U.S. Pat. No. 8,711,183; 2007/0056858, now U.S. Pat.No. 8,298,389; 2007/0068807, now U.S. Pat. No. 7,846,311; 2007/0227911,now U.S. Pat. No. 7,887,682; 2007/0233013; 2008/0081977, now U.S. Pat.No. 7,618,369; 2008/0161666; and 2009/0054748, now U.S. Pat. No.7,885,698; U.S. patent application Ser. No. 11/396,135, now U.S. Pat.No. 7,620,438, Ser. Nos. 11/537,984, 12/131,012; 12/242,823, now U.S.Pat. No. 8,219,173; and Ser. No. 12/363,712, now U.S. Pat. No.8,346,335; and U.S. Provisional Application Ser. Nos. 61/149,639;61/155,889; 61/155,891; 61/155,893; 61/165,499; 61/230,686; 61/227,967and 61/238,461.

DETAILED DESCRIPTION

Before the present disclosure is described, it is to be understood thatthis disclosure is not limited to particular embodiments described, assuch may, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting, since the scope ofthe present disclosure will be limited only by the appended claims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed within the disclosure. The upper and lowerlimits of these smaller ranges may independently be included in thesmaller ranges as also encompassed within the disclosure, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included in the disclosure.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise.

As will be apparent to those of skill in the art upon reading thisdisclosure, each of the individual embodiments described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentdisclosure.

The figures shown herein are not necessarily drawn to scale, with somecomponents and features being exaggerated for clarity.

Generally, embodiments of the present disclosure relate to methods anddevices for detecting at least one analyte such as glucose in bodyfluid. Embodiments relate to the continuous and/or automatic in vivomonitoring of the level of one or more analytes using a continuousanalyte monitoring system that includes an analyte sensor at least aportion of which is to be positioned beneath a skin surface of a userfor a period of time and/or the discrete monitoring of one or moreanalytes using an in vitro blood glucose (“BG”) meter and an analytetest strip. Embodiments include combined or combinable devices, systemsand methods and/or transferring data between an in vivo continuoussystem and a BG meter system.

Accordingly, embodiments include analyte monitoring devices and systemsthat include an analyte sensor—at least a portion of which ispositionable beneath the skin of the user—for the in vivo detection, ofan analyte, such as glucose, lactate, and the like, in a body fluid.Embodiments include wholly implantable analyte sensors and analytesensors in which only a portion of the sensor is positioned under theskin and a portion of the sensor resides above the skin, e.g., forcontact to a transmitter, receiver, transceiver, processor, etc. Thesensor may be, for example, subcutaneously positionable in a patient forthe continuous or periodic monitoring of a level of an analyte in apatient's interstitial fluid. For the purposes of this description,continuous monitoring and periodic monitoring will be usedinterchangeably, unless noted otherwise. The sensor response may becorrelated and/or converted to analyte levels in blood or other fluids.In certain embodiments, an analyte sensor may be positioned in contactwith interstitial fluid to detect the level of glucose, which detectedglucose may be used to infer the glucose level in the patient'sbloodstream. Analyte sensors may be insertable into a vein, artery, orother portion of the body containing fluid. Embodiments of the analytesensors of the subject disclosure may be configured for monitoring thelevel of the analyte over a time period which may range from minutes,hours, days, weeks, or longer.

Of interest are analyte sensors, such as glucose sensors, that arecapable of in vivo detection of an analyte for about one hour or more,e.g., about a few hours or more, e.g., about a few days of more, e.g.,about three days or more, e.g., about five days or more, e.g., aboutseven days or more, e.g., about several weeks or at least one month.Future analyte levels may be predicted based on information obtained,e.g., the current analyte level at time to, the rate of change of theanalyte, etc. Predictive alarms may notify the user of a predictedanalyte level that may be of concern in advance of the user's analytelevel reaching the future level. This provides the user an opportunityto take corrective action.

FIG. 1 shows a data monitoring and management system such as, forexample, an analyte (e.g., glucose) monitoring system 100 in accordancewith certain embodiments. Embodiments of the subject disclosure arefurther described primarily with respect to glucose monitoring devicesand systems, and methods of glucose detection, for convenience only andsuch description is in no way intended to limit the scope of thedisclosure. It is to be understood that the analyte monitoring systemmay be configured to monitor a variety of analytes at the same time orat different times.

Analytes that may be monitored include, but are not limited to, acetylcholine, amylase, bilirubin, cholesterol, chorionic gonadotropin,creatine kinase (e.g., CK-MB), creatine, creatinine, DNA, fructosamine,glucose, glutamine, growth hormones, hormones, ketone bodies, lactate,peroxide, prostate-specific antigen, prothrombin, RNA, thyroidstimulating hormone, and troponin. The concentration of drugs, such as,for example, antibiotics (e.g., gentamicin, vancomycin, and the like),digitoxin, digoxin, drugs of abuse, theophylline, and warfarin, may alsobe monitored. In those embodiments that monitor more than one analyte,the analytes may be monitored at the same or different times.

The analyte monitoring system 100 includes a sensor 101, a dataprocessing unit 102 connectable to the sensor 101, and a primaryreceiver unit 104 which is configured to communicate with the dataprocessing unit 102 via a communication link 103. In certainembodiments, the primary receiver unit 104 may be further configured totransmit data to a data processing terminal 105 to evaluate or otherwiseprocess or format data received by the primary receiver unit 104. Thedata processing terminal 105 may be configured to receive data directlyfrom the data processing unit 102 via a communication link which mayoptionally be configured for bi-directional communication. Further, thedata processing unit 102 may include a transmitter or a transceiver totransmit and/or receive data to and/or from the primary receiver unit104 and/or the data processing terminal 105 and/or optionally thesecondary receiver unit 106.

Also shown in FIG. 1 is an optional secondary receiver unit 106 which isoperatively coupled to the communication link and configured to receivedata transmitted from the data processing unit 102. The secondaryreceiver unit 106 may be configured to communicate with the primaryreceiver unit 104, as well as the data processing terminal 105. Thesecondary receiver unit 106 may be configured for bi-directionalwireless communication with each of the primary receiver unit 104 andthe data processing terminal 105. As discussed in further detail below,in certain embodiments the secondary receiver unit 106 may be ade-featured receiver as compared to the primary receiver, i.e., thesecondary receiver may include a limited or minimal number of functionsand features as compared with the primary receiver unit 104. As such,the secondary receiver unit 106 may include a smaller (in one or more,including all, dimensions), compact housing or embodied in a device suchas a wrist watch, arm band, etc., for example. Alternatively, thesecondary receiver unit 106 may be configured with the same orsubstantially similar functions and features as the primary receiverunit 104. The secondary receiver unit 106 may include a docking portionto be mated with a docking cradle unit for placement by, e.g., thebedside for night time monitoring, and/or a bi-directional communicationdevice. A docking cradle may recharge a powers supply.

Only one sensor 101, data processing unit 102 and data processingterminal 105 are shown in the embodiment of the analyte monitoringsystem 100 illustrated in FIG. 1. However, it will be appreciated by oneof ordinary skill in the art that the analyte monitoring system 100 mayinclude more than one sensor 101 and/or more than one data processingunit 102, and/or more than one data processing terminal 105. Multiplesensors may be positioned in a patient for analyte monitoring at thesame or different times. In certain embodiments, analyte informationobtained by a first positioned sensor may be employed as a comparison toanalyte information obtained by a second sensor. This may be useful toconfirm or validate analyte information obtained from one or both of thesensors. Such redundancy may be useful if analyte information iscontemplated in critical therapy-related decisions. In certainembodiments, a first sensor may be used to calibrate a second sensor.

The analyte monitoring system 100 may be a continuous monitoring system,or semi-continuous, or a discrete monitoring system. In amulti-component environment, each component may be configured to beuniquely identified by one or more of the other components in the systemso that communication conflict may be readily resolved between thevarious components within the analyte monitoring system 100. Forexample, unique IDs, communication channels, and the like, may be used.

In certain embodiments, the sensor 101 is physically positioned in or onthe body of a user whose analyte level is being monitored. The sensor101 may be configured to at least periodically sample the analyte levelof the user and convert the sampled analyte level into a correspondingsignal for transmission by the data processing unit 102. The dataprocessing unit 102 is coupleable to the sensor 101 so that both devicesare positioned in or on the user's body, with at least a portion of theanalyte sensor 101 positioned transcutaneously. The data processing unitmay include a fixation element such as adhesive or the like to secure itto the user's body. A mount (not shown) attachable to the user andmateable with the data processing unit 102 may be used. For example, amount may include an adhesive surface. The data processing unit 102performs data processing functions, where such functions may include,but are not limited to, filtering and encoding of data signals, each ofwhich corresponds to a sampled analyte level of the user, fortransmission to the primary receiver unit 104 via the communication link103. In one embodiment, the sensor 101 or the data processing unit 102or a combined sensor/data processing unit may be wholly implantableunder the skin layer of the user.

In certain embodiments, the primary receiver unit 104 may include ananalog interface section including an RF receiver and an antenna that isconfigured to communicate with the data processing unit 102 via thecommunication link 103, and a data processing section for processing thereceived data from the data processing unit 102 such as data decoding,error detection and correction, data clock generation, data bitrecovery, etc., or any combination thereof.

In operation, the primary receiver unit 104, in certain embodiments, isconfigured to synchronize with the data processing unit 102 to uniquelyidentify the data processing unit 102, based on, for example, anidentification information of the data processing unit 102, andthereafter, to periodically receive signals transmitted from the dataprocessing unit 102 associated with the monitored analyte levelsdetected by the sensor 101.

Referring again to FIG. 1, the data processing terminal 105 may includea personal computer, a portable computer such as a laptop or a handhelddevice (e.g., personal digital assistants (PDAs), telephone such as acellular phone (e.g., a multimedia and Internet-enabled mobile phonesuch as an iPhone or similar phone), mp3 player, pager, and the like),drug delivery device, each of which may be configured for datacommunication with the receiver via a wired or a wireless connection.Additionally, the data processing terminal 105 may further be connectedto a data network (not shown) for storing, retrieving, updating, and/oranalyzing data corresponding to the detected analyte level of the user.

The data processing terminal 105 may include an infusion device such asan insulin infusion pump or the like, which may be configured toadminister insulin to patients, and which may be configured tocommunicate with the primary receiver unit 104 for receiving, amongothers, the measured analyte level. Alternatively, the primary receiverunit 104 may be configured to integrate an infusion device therein sothat the primary receiver unit 104 is configured to administer insulin(or other appropriate drug) therapy to patients, for example, foradministering and modifying basal profiles, as well as for determiningappropriate boluses for administration based on, among others, thedetected analyte levels received from the data processing unit 102. Aninfusion device may be an external device or an internal device (whollyimplantable in a user).

In certain embodiments, the data processing terminal 105, which mayinclude an insulin pump, may be configured to receive the analytesignals from the data processing unit 102, and thus, incorporate thefunctions of the primary receiver unit 104 including data processing formanaging the patient's insulin therapy and analyte monitoring. Incertain embodiments, the communication link 103, as well as one or moreof the other communication interfaces shown in FIG. 1, may use one ormore of: an RF communication protocol, an infrared communicationprotocol, a Bluetooth® enabled communication protocol, an 802.11xwireless communication protocol, or an equivalent wireless communicationprotocol which would allow secure, wireless communication of severalunits (for example, per HIPAA requirements), while avoiding potentialdata collision and interference.

FIG. 2 shows a block diagram of an embodiment of a data processing unitof the data monitoring and detection system shown in FIG. 1. User input202 and/or interface components may be included or a data processingunit may be free of user input and/or interface components. In certainembodiments, one or more application specific integrated circuits (ASIC)may be used to implement one or more functions or routines associatedwith the operations of the data processing unit (and/or receiver unit)using for example one or more state machines and buffers.

Further shown in FIG. 2 are serial communication section 205 and an RFtransmitter 206, each of which is also operatively coupled to thetransmitter processor 204. Also shown in FIG. 2 is a dedicated link 209from the analog interface 201 to serial communication section 205.Moreover, a power supply 207, such as a battery, may also be provided inthe data processing unit 102 to provide the necessary power for the dataprocessing unit 102. Additionally, as can be seen from the Figure, clock208 may be provided to, among others, supply real time information tothe transmitter processor 204.

As can be seen in the embodiment of FIG. 2, the sensor 101 (FIG. 1)includes four contacts, three of which are electrodes—working electrode(W) 210, reference electrode (R) 212, and counter electrode (C) 213,each operatively coupled to the analog interface 201 of the dataprocessing unit 102. This embodiment also shows optional guard contact(G) 211. Fewer or greater electrodes may be employed. For example, thecounter and reference electrode functions may be served by a singlecounter/reference electrode, there may be more than one workingelectrode and/or reference electrode and/or counter electrode, etc.

Referring yet again to FIG. 2, a temperature measurement section 203 ofthe data processing unit 102 is configured to monitor the temperature ofthe skin near the sensor insertion site. The temperature reading may beused to adjust the analyte readings obtained from the analog interface201. Also shown is a leak detection circuit 214 coupled to the guardcontact (G) 211 and the processor 204 in the data processing unit 102 ofthe analyte monitoring system 100. The leak detection circuit 214 may beconfigured to detect leakage current in the sensor 101 to determinewhether the measured sensor data are corrupt or whether the measureddata from the sensor 101 is accurate. Such detection may trigger anotification to the user.

FIG. 3 is a block diagram of an embodiment of a receiver/monitor unitsuch as the primary receiver unit 104 of the data monitoring andmanagement system shown in FIG. 1. The primary receiver unit 104includes one or more of: a blood glucose test strip interface 301, an RFreceiver 302, an input 303, a temperature detection section 304, and aclock 305, each of which is operatively coupled to a processing andstorage section 307. The primary receiver unit 104 also includes a powersupply 306 operatively coupled to a power conversion and monitoringsection 308. Further, the power conversion and monitoring section 308 isalso coupled to the receiver processor 307. Moreover, also shown are areceiver serial communication section 309, and an output 310, eachoperatively coupled to the processing and storage unit 307. The receivermay include user input and/or interface components or may be free ofuser input and/or interface components.

In certain embodiments, the test strip interface 301 includes a glucoselevel testing portion to receive a blood (or other body fluid sample)glucose test or information related thereto. For example, the interfacemay include a test strip port to receive a glucose test strip. Thedevice may determine the glucose level of the test strip, and optionallydisplay (or otherwise notice) the glucose level on the output 310 of theprimary receiver unit 104. Any suitable test strip may be employed,e.g., test strips that only require a very small amount (e.g., onemicroliter or less, e.g., 0.5 microliter or less, e.g., 0.1 microliteror less), of applied sample to the strip in order to obtain accurateglucose information, e.g. Freestyle® blood glucose test strips fromAbbott Diabetes Care Inc. Glucose information obtained by the in vitroglucose testing device may be used for a variety of purposes,computations, etc. For example, the information may be used to calibratesensor 101, confirm results of the sensor 101 to increase the confidencethereof (e.g., in instances in which information obtained by sensor 101is employed in therapy related decisions), etc.

In further embodiments, the data processing unit 102 and/or the primaryreceiver unit 104 and/or the secondary receiver unit 106, and/or thedata processing terminal/infusion section 105 may be configured toreceive the blood glucose value wirelessly over a communication linkfrom, for example, a blood glucose meter. In further embodiments, a usermanipulating or using the analyte monitoring system 100 (FIG. 1) maymanually input the blood glucose value using, for example, a userinterface (for example, a keyboard, keypad, voice commands, and thelike) incorporated in the one or more of the data processing unit 102,the primary receiver unit 104, secondary receiver unit 106, or the dataprocessing terminal/infusion section 105.

Additional detailed descriptions are provided in U.S. Pat. Nos.5,262,035; 5,264,104; 5,262,305; 5,320,715; 5,593,852; 6,175,752;6,650,471; 6,746, 582, and in application Ser. No. 10/745,878 filed Dec.26, 2003, now U.S. Pat. No. 7,811,231, entitled “Continuous GlucoseMonitoring System and Methods of Use”, each of which is incorporatedherein by reference.

FIG. 4 schematically shows an embodiment of an analyte sensor inaccordance with the present disclosure. This sensor embodiment includeselectrodes 401, 402 and 403 on a base 404. Electrodes (and/or otherfeatures) may be applied or otherwise processed using any suitabletechnology, e.g., chemical vapor deposition (CVD), physical vapordeposition, sputtering, reactive sputtering, printing, coating, ablating(e.g., laser ablation), painting, dip coating, etching, and the like.Materials include, but are not limited, to aluminum, carbon (such asgraphite), cobalt, copper, gallium, gold, indium, iridium, iron, lead,magnesium, mercury (as an amalgam), nickel, niobium, osmium, palladium,platinum, rhenium, rhodium, selenium, silicon (e.g., dopedpolycrystalline silicon), silver, tantalum, tin, titanium, tungsten,uranium, vanadium, zinc, zirconium, mixtures thereof, and alloys,oxides, or metallic compounds of these elements.

The sensor may be wholly implantable in a user or may be configured sothat only a portion is positioned within (internal) a user and anotherportion outside (external) a user. For example, the sensor 400 mayinclude a portion positionable above a surface of the skin 410, and aportion positioned below the skin. In such embodiments, the externalportion may include contacts (connected to respective electrodes of thesecond portion by traces) to connect to another device also external tothe user such as a transmitter unit. While the embodiment of FIG. 4shows three electrodes side-by-side on the same surface of base 404,other configurations are contemplated, e.g., fewer or greaterelectrodes, some or all electrodes on different surfaces of the base orpresent on another base, some or all electrodes stacked together,electrodes of differing materials and dimensions, etc.

FIG. 5A shows a perspective view of an embodiment of an electrochemicalanalyte sensor 500 having a first portion (which in this embodiment maybe characterized as a major portion) positionable above a surface of theskin 510, and a second portion (which in this embodiment may becharacterized as a minor portion) that includes an insertion tip 530positionable below the skin, e.g., penetrating through the skin andinto, e.g., the subcutaneous space 520, in contact with the user'sbiofluid such as interstitial fluid. Contact portions of a workingelectrode 501, a reference electrode 502, and a counter electrode 503are positioned on the portion of the sensor 500 situated above the skinsurface 510. Working electrode 501, a reference electrode 502, and acounter electrode 503 are shown at the second section and particularlyat the insertion tip 530. Traces may be provided from the electrode atthe tip to the contact, as shown in FIG. 5A. It is to be understood thatgreater or fewer electrodes may be provided on a sensor. For example, asensor may include more than one working electrode and/or the counterand reference electrodes may be a single counter/reference electrode,etc.

FIG. 5B shows a cross sectional view of a portion of the sensor 500 ofFIG. 5A. The electrodes 501, 502 and 503, of the sensor 500 as well asthe substrate and the dielectric layers are provided in a layeredconfiguration or construction. For example, as shown in FIG. 5B, in oneaspect, the sensor 500 (such as the sensor 101 FIG. 1), includes asubstrate layer 504, and a first conducting layer 501, such as carbon,gold, etc., disposed on at least a portion of the substrate layer 504,and which may provide the working electrode. Also shown disposed on atleast a portion of the first conducting layer 501 is a sensing layer508.

A first insulation layer such as a first dielectric layer 505 isdisposed or layered on at least a portion of the first conducting layer501, and further, a second conducting layer 509 may be disposed orstacked on top of at least a portion of the first insulation layer (ordielectric layer) 505. As shown in FIG. 5B, the second conducting layer509 may provide the reference electrode 502, and in one aspect, mayinclude a layer of silver/silver chloride (Ag/AgCl), gold, etc.

A second insulation layer 506 such as a dielectric layer in oneembodiment may be disposed or layered on at least a portion of thesecond conducting layer 509. Further, a third conducting layer 503 mayprovide the counter electrode 503. It may be disposed on at least aportion of the second insulation layer 506. Finally, a third insulationlayer 507 may be disposed or layered on at least a portion of the thirdconducting layer 503. In this manner, the sensor 500 may be layered suchthat at least a portion of each of the conducting layers is separated bya respective insulation layer (for example, a dielectric layer). Theembodiment of FIGS. 5A and 5B show the layers having different lengths.Some or all of the layers may have the same or different lengths and/orwidths.

In certain embodiments, some or all of the electrodes 501, 502, 503 maybe provided on the same side of the substrate 504 in the layeredconstruction as described above, or alternatively, may be provided in aco-planar manner such that two or more electrodes may be positioned onthe same plane (e.g., side-by side (e.g., parallel) or angled relativeto each other) on the substrate 504. For example, co-planar electrodesmay include a suitable spacing there between and/or include dielectricmaterial or insulation material disposed between the conductinglayers/electrodes. Furthermore, in certain embodiments, one or more ofthe electrodes 501, 502, 503 may be disposed on opposing sides of thesubstrate 504. In such embodiments, contact pads may be on the same ordifferent sides of the substrate. For example, an electrode may be on afirst side and its respective contact may be on a second side, e.g., atrace connecting the electrode and the contact may traverse through thesubstrate.

As noted above, analyte sensors may include an analyte-responsive enzymeto provide a sensing component or sensing layer. Some analytes, such asoxygen, can be directly electrooxidized or electroreduced on a sensor,and more specifically at least on a working electrode of a sensor. Otheranalytes, such as glucose and lactate, require the presence of at leastone electron transfer agent and/or at least one catalyst to facilitatethe electrooxidation or electroreduction of the analyte. Catalysts mayalso be used for those analytes, such as oxygen, that can be directlyelectrooxidized or electroreduced on the working electrode. For theseanalytes, each working electrode includes a sensing layer (see forexample sensing layer 408 of FIG. 5B) proximate to or on a surface of aworking electrode. In many embodiments, a sensing layer is formed nearor on only a small portion of at least a working electrode.

The sensing layer includes one or more components designed to facilitatethe electrochemical oxidation or reduction of the analyte. The sensinglayer may include, for example, a catalyst to catalyze a reaction of theanalyte and produce a response at the working electrode, an electrontransfer agent to transfer electrons between the analyte and the workingelectrode (or other component), or both.

A variety of different sensing layer configurations may be used. Incertain embodiments, the sensing layer is deposited on the conductivematerial of a working electrode. The sensing layer may extend beyond theconductive material of the working electrode. In some cases, the sensinglayer may also extend over other electrodes, e.g., over the counterelectrode and/or reference electrode (or counter/reference is provided).

A sensing layer that is in direct contact with the working electrode maycontain an electron transfer agent to transfer electrons directly orindirectly between the analyte and the working electrode, and/or acatalyst to facilitate a reaction of the analyte. For example, aglucose, lactate, or oxygen electrode may be formed having a sensinglayer which contains a catalyst, such as glucose oxidase, lactateoxidase, or laccase, respectively, and an electron transfer agent thatfacilitates the electrooxidation of the glucose, lactate, or oxygen,respectively.

In other embodiments the sensing layer is not deposited directly on theworking electrode. Instead, the sensing layer 64 may be spaced apartfrom the working electrode, and separated from the working electrode,e.g., by a separation layer. A separation layer may include one or moremembranes or films or a physical distance. In addition to separating theworking electrode from the sensing layer the separation layer may alsoact as a mass transport limiting layer and/or an interferent eliminatinglayer and/or a biocompatible layer.

In certain embodiments which include more than one working electrode,one or more of the working electrodes may not have a correspondingsensing layer, or may have a sensing layer which does not contain one ormore components (e.g., an electron transfer agent and/or catalyst)needed to electrolyze the analyte. Thus, the signal at this workingelectrode may correspond to background signal which may be removed fromthe analyte signal obtained from one or more other working electrodesthat are associated with fully-functional sensing layers by, forexample, subtracting the signal.

In certain embodiments, the sensing layer includes one or more electrontransfer agents. Electron transfer agents that may be employed areelectroreducible and electrooxidizable ions or molecules having redoxpotentials that are a few hundred millivolts above or below the redoxpotential of the standard calomel electrode (SCE). The electron transferagent may be organic, organometallic, or inorganic. Examples of organicredox species are quinones and species that in their oxidized state havequinoid structures, such as Nile blue and indophenol. Examples oforganometallic redox species are metallocenes such as ferrocene.Examples of inorganic redox species are hexacyanoferrate (III),ruthenium hexamine etc.

In certain embodiments, electron transfer agents have structures orcharges which prevent or substantially reduce the diffusional loss ofthe electron transfer agent during the period of time that the sample isbeing analyzed. For example, electron transfer agents include, but arenot limited to, a redox species, e.g., bound to a polymer which can inturn be disposed on or near the working electrode. The bond between theredox species and the polymer may be covalent, coordinative, or ionic.Although any organic, organometallic or inorganic redox species may bebound to a polymer and used as an electron transfer agent, in certainembodiments the redox species is a transition metal compound or complex,e.g., osmium, ruthenium, iron, and cobalt compounds or complexes. Itwill be recognized that many redox species described for use with apolymeric component may also be used, without a polymeric component.

One type of polymeric electron transfer agent contains a redox speciescovalently bound in a polymeric composition. An example of this type ofmediator is poly(vinylferrocene). Another type of electron transferagent contains an ionically-bound redox species. This type of mediatormay include a charged polymer coupled to an oppositely charged redoxspecies. Examples of this type of mediator include a negatively chargedpolymer coupled to a positively charged redox species such as an osmiumor ruthenium polypyridyl cation. Another example of an ionically-boundmediator is a positively charged polymer such as quaternizedpoly(4-vinyl pyridine) or poly(1-vinyl imidazole) coupled to anegatively charged redox species such as ferricyanide or ferrocyanide.In other embodiments, electron transfer agents include a redox speciescoordinatively bound to a polymer. For example, the mediator may beformed by coordination of an osmium or cobalt 2,2′-bipyridyl complex topoly(l-vinyl imidazole) or poly(4-vinyl pyridine).

Suitable electron transfer agents are osmium transition metal complexeswith one or more ligands, each ligand having a nitrogen-containingheterocycle such as 2,2′-bipyridine, 1,10-phenanthroline, 1-methyl,2-pyridyl biimidazole, or derivatives thereof. The electron transferagents may also have one or more ligands covalently bound in a polymer,each ligand having at least one nitrogen-containing heterocycle, such aspyridine, imidazole, or derivatives thereof. One example of an electrontransfer agent includes (a) a polymer or copolymer having pyridine orimidazole functional groups and (b) osmium cations complexed with twoligands, each ligand containing 2,2′-bipyridine, 1,10-phenanthroline, orderivatives thereof, the two ligands not necessarily being the same.Some derivatives of 2,2′-bipyridine for complexation with the osmiumcation include, but are not limited to, 4,4′-dimethyl-2,2′-bipyridineand mono-, di-, and polyalkoxy-2,2′-bipyridines, such as4,4′-dimethoxy-2,2′-bipyridine. Derivatives of 1,10-phenanthroline forcomplexation with the osmium cation include, but are not limited to,4,7-dimethyl-1,10-phenanthroline and mono, di-, andpolyalkoxy-1,10-phenanthrolines, such as4,7-dimethoxy-1,10-phenanthroline. Polymers for complexation with theosmium cation include, but are not limited to, polymers and copolymersof poly(1-vinyl imidazole) (referred to as “PVI”) and poly(4-vinylpyridine) (referred to as “PVP”). Suitable copolymer substituents ofpoly(1-vinyl imidazole) include acrylonitrile, acrylamide, andsubstituted or quaternized N-vinyl imidazole, e.g., electron transferagents with osmium complexed to a polymer or copolymer of poly(1-vinylimidazole).

Embodiments may employ electron transfer agents having a redox potentialranging from about −200 mV to about +200 mV versus the standard calomelelectrode (SCE). The sensing layer may also include a catalyst which iscapable of catalyzing a reaction of the analyte. The catalyst may also,in some embodiments, act as an electron transfer agent. One example of asuitable catalyst is an enzyme which catalyzes a reaction of theanalyte. For example, a catalyst, such as a glucose oxidase, glucosedehydrogenase (e.g., pyrroloquinoline quinone (PQQ), dependent glucosedehydrogenase, flavine adenine dinucleotide (FAD), or nicotinamideadenine dinucleotide (NAD) dependent glucose dehydrogenase), may be usedwhen the analyte of interest is glucose. A lactate oxidase or lactatedehydrogenase may be used when the analyte of interest is lactate.Laccase may be used when the analyte of interest is oxygen or whenoxygen is generated or consumed in response to a reaction of theanalyte.

The sensing layer may also include a catalyst which is capable ofcatalyzing a reaction of the analyte. The catalyst may also, in someembodiments, act as an electron transfer agent. One example of asuitable catalyst is an enzyme which catalyzes a reaction of theanalyte. For example, a catalyst, such as a glucose oxidase, glucosedehydrogenase (e.g., pyrroloquinoline quinone (PQQ), dependent glucosedehydrogenase or oligosaccharide dehydrogenase, flavine adeninedinucleotide (FAD) dependent glucose dehydrogenase, nicotinamide adeninedinucleotide (NAD) dependent glucose dehydrogenase), may be used whenthe analyte of interest is glucose. A lactate oxidase or lactatedehydrogenase may be used when the analyte of interest is lactate.Laccase may be used when the analyte of interest is oxygen or whenoxygen is generated or consumed in response to a reaction of theanalyte.

In certain embodiments, a catalyst may be attached to a polymer, crosslinking the catalyst with another electron transfer agent (which, asdescribed above, may be polymeric. A second catalyst may also be used incertain embodiments. This second catalyst may be used to catalyze areaction of a product compound resulting from the catalyzed reaction ofthe analyte. The second catalyst may operate with an electron transferagent to electrolyze the product compound to generate a signal at theworking electrode. Alternatively, a second catalyst may be provided inan interferent-eliminating layer to catalyze reactions that removeinterferents.

Certain embodiments include a Wired Enzyme™ sensing layer (AbbottDiabetes Care) that works at a gentle oxidizing potential, e.g., apotential of about +40 mV. This sensing layer uses an osmium (Os)-basedmediator designed for low potential operation and is stably anchored ina polymeric layer. Accordingly, in certain embodiments the sensingelement is a redox active component that includes (1) Osmium-basedmediator molecules attached by stable (bidente) ligands anchored to apolymeric backbone, and (2) glucose oxidase enzyme molecules. These twoconstituents are crosslinked together.

A mass transport limiting layer (not shown), e.g., an analyte fluxmodulating layer, may be included with the sensor to act as adiffusion-limiting barrier to reduce the rate of mass transport of theanalyte, for example, glucose or lactate, into the region around theworking electrodes. The mass transport limiting layers are useful inlimiting the flux of an analyte to a working electrode in anelectrochemical sensor so that the sensor is linearly responsive over alarge range of analyte concentrations and is easily calibrated. Masstransport limiting layers may include polymers and may be biocompatible.A mass transport limiting layer may provide many functions, e.g.,biocompatibility and/or interferent-eliminating, etc.

In certain embodiments, a mass transport limiting layer is a membranecomposed of crosslinked polymers containing heterocyclic nitrogengroups, such as polymers of polyvinylpyridine and polyvinylimidazole.Embodiments also include membranes that are made of a polyurethane, orpolyether urethane, or chemically related material, or membranes thatare made of silicone, and the like.

A membrane may be formed by crosslinking in situ a polymer, modifiedwith a zwitterionic moiety, a non-pyridine copolymer component, andoptionally another moiety that is either hydrophilic or hydrophobic,and/or has other desirable properties, in an alcohol-buffer solution.The modified polymer may be made from a precursor polymer containingheterocyclic nitrogen groups. For example, a precursor polymer may bepolyvinylpyridine or polyvinylimidazole. Optionally, hydrophilic orhydrophobic modifiers may be used to “fine-tune” the permeability of theresulting membrane to an analyte of interest. Optional hydrophilicmodifiers, such as poly(ethylene glycol), hydroxyl or polyhydroxylmodifiers, may be used to enhance the biocompatibility of the polymer orthe resulting membrane.

A membrane may be formed in situ by applying an alcohol-buffer solutionof a crosslinker and a modified polymer over an enzyme-containingsensing layer and allowing the solution to cure for about one to twodays or other appropriate time period. The crosslinker-polymer solutionmay be applied to the sensing layer by placing a droplet or droplets ofthe solution on the sensor, by dipping the sensor into the solution, orthe like. Generally, the thickness of the membrane is controlled by theconcentration of the solution, by the number of droplets of the solutionapplied, by the number of times the sensor is dipped in the solution, orby any combination of these factors. A membrane applied in this mannermay have any combination of the following functions: (1) mass transportlimitation, i.e., reduction of the flux of analyte that can reach thesensing layer, (2) biocompatibility enhancement, or (3) interferentreduction.

The electrochemical sensors may employ any suitable measurementtechnique. For example, may detect current or may employ potentiometry.Technique may include, but are not limited to, amperometry, coulometry,and voltammetry. In some embodiments, sensing systems may be optical,colorimetric, and the like.

In certain embodiments, the sensing system detects hydrogen peroxide toinfer glucose levels. For example, a hydrogen peroxide-detecting sensormay be constructed in which a sensing layer includes enzyme such asglucose oxides, glucose dehydrogenase, or the like, and is positionedproximate to the working electrode. The sending layer may be covered bya membrane that is selectively permeable to glucose. Once the glucosepasses through the membrane, it is oxidized by the enzyme and reducedglucose oxidase can then be oxidized by reacting with molecular oxygento produce hydrogen peroxide.

Certain embodiments include a hydrogen peroxide-detecting sensorconstructed from a sensing layer prepared by crosslinking two componentstogether, for example: (1) a redox compound such as a redox polymercontaining pendent Os polypyridyl complexes with oxidation potentials ofabout +200 mV vs. SCE, and (2) periodate oxidized horseradish peroxidase(HRP). Such a sensor functions in a reductive mode; the workingelectrode is controlled at a potential negative to that of the Oscomplex, resulting in mediated reduction of hydrogen peroxide throughthe HRP catalyst.

In another example, a potentiometric sensor can be constructed asfollows. A glucose-sensing layer is constructed by crosslinking together(1) a redox polymer containing pendent Os polypyridyl complexes withoxidation potentials from about −200 mV to +200 mV vs. SCE, and (2)glucose oxidase. This sensor can then be used in a potentiometric mode,by exposing the sensor to a glucose containing solution, underconditions of zero current flow, and allowing the ratio ofreduced/oxidized Os to reach an equilibrium value. The reduced/oxidizedOs ratio varies in a reproducible way with the glucose concentration,and will cause the electrode's potential to vary in a similar way.

A sensor may also include an active agent such as an anticlotting and/orantiglycolytic agent(s) disposed on at least a portion a sensor that ispositioned in a user. An anticlotting agent may reduce or eliminate theclotting of blood or other body fluid around the sensor, particularlyafter insertion of the sensor. Examples of useful anticlotting agentsinclude heparin and tissue plasminogen activator (TPA), as well as otherknown anticlotting agents. Embodiments may include an antiglycolyticagent or precursor thereof. Examples of antiglycolytic agents areglyceraldehyde, fluoride ion, and mannose.

Sensors may be configured to require no system calibration or no usercalibration. For example, a sensor may be factory calibrated and neednot require further calibrating. In certain embodiments, calibration maybe required, but may be done without user intervention, i.e., may beautomatic. In those embodiments in which calibration by the user isrequired, the calibration may be according to a predetermined scheduleor may be dynamic, i.e., the time for which may be determined by thesystem on a real-time basis according to various factors, such as, butnot limited to, glucose concentration and/or temperature and/or rate ofchange of glucose, etc.

Calibration may be accomplished using an in vitro test strip (or otherreference), e.g., a small sample test strip such as a test strip thatrequires less than about 1 microliter of sample (for example Freestyle®blood glucose monitoring test strips from Abbott Diabetes Care). Forexample, test strips that require less than about 1 nanoliter of samplemay be used. In certain embodiments, a sensor may be calibrated usingonly one sample of body fluid per calibration event. For example, a userneed only lance a body part one time to obtain sample for a calibrationevent (e.g., for a test strip), or may lance more than one time within ashort period of time if an insufficient volume of sample is firstlyobtained. Embodiments include obtaining and using multiple samples ofbody fluid for a given calibration event, where glucose values of eachsample are substantially similar. Data obtained from a given calibrationevent may be used independently to calibrate or combined with dataobtained from previous calibration events, e.g., averaged includingweighted averaged, etc., to calibrate. In certain embodiments, a systemneed only be calibrated once by a user, where recalibration of thesystem is not required.

Analyte systems may include an optional alarm system that, e.g., basedon information from a processor, warns the patient of a potentiallydetrimental condition of the analyte. For example, if glucose is theanalyte, an alarm system may warn a user of conditions such ashypoglycemia and/or hyperglycemia and/or impending hypoglycemia, and/orimpending hyperglycemia. An alarm system may be triggered when analytelevels approach, reach or exceed a threshold value. An alarm system mayalso, or alternatively, be activated when the rate of change, oracceleration of the rate of change, in analyte level increase ordecrease, approaches, reaches or exceeds a threshold rate oracceleration. A system may also include system alarms that notify a userof system information such as battery condition, calibration, sensordislodgment, sensor malfunction, etc. Alarms may be, for example,auditory and/or visual. Other sensory-stimulating alarm systems may beused including alarm systems which heat, cool, vibrate, or produce amild electrical shock when activated.

Referring back to the figures, FIG. 6 illustrates steps for setting,determining or programming an alarm parameter based on glycemicexcursion events in one embodiment of the present disclosure. The alarmparameter may be based on, but not limited to, a determined rate ofoccurrence of a glycemic excursion event (610) such as hypoglycemia orhyperglycemia, a determined frequency of alarm activation based on theglycemic excursion event (620), and/or a determined glucose levelassociated with the alarm activation (630).

In one aspect, the rate of occurrence of a glycemic excursion event(610) may be determined by analyzing glycemic related data for apredetermined time period, as illustrated in the flow chart of FIG. 7.Referring to FIG. 7, in one embodiment, the rate of occurrence of aglycemic excursion event is determined by monitoring a glucose level ofa patient for a predetermined time period (710). During thispredetermined time period, the occurrence or the frequency of theoccurrence of the glucose level of the patient crossing or transcendinga predetermined threshold is detected (720). The predeterminedthreshold, in one aspect, may be based on one or more threshold levelsor parameters associated with one or more conditions, such as, forexample, but not limited to, hypoglycemic condition, hyperglycemiccondition, impending hyperglycemic or impending hypoglycemic conditions,a rate of change of the glucose or analyte level exceeding a set orprogrammed rate, or a rate of acceleration or deceleration of theglucose or analyte level fluctuation. For example, the predeterminedthreshold for mild hypoglycemia may be associated with a blood glucoselevel of approximately 70 mg/dL and the threshold for moderatehypoglycemia may be associated with a blood glucose level ofapproximately 60 mg/dL. Referring back to FIG. 7, the detection of theglucose level transcending or crossing the predetermined threshold maybe stored in a memory or a suitable storage device such as random accessmemory (RAM), electrically programmable random access memory (EPROM),Flash memory and the like, and the stored information may be used todetermine the rate of occurrence of the glycemic event during thepredetermined time period (730).

Referring back to FIG. 6, the frequency of an alarm activationassociated with the glycemic excursion event (620) is determined, aswell as the glucose level associated with the alarm activation (630),which, in one aspect, is determined based on analyte sensor datareceived from a transcutaneous analyte sensor, such as a glucose sensor.Once the rate of occurrence of the glycemic excursion event, and thefrequency of alarm activation and associated glucose level aredetermined, an alarm parameter may be set or programmed (orprogrammable) based on the determined information (640). In otheraspects, information, such as the rate of change of the glucose levelassociated with the glycemic excursion event or the associated alarmactivation or trigger event, may be determined and used to, in part,base or determine the setting/establishing of the alarm parameter.Moreover, once the alarm parameter is set or established, the alarmparameter may be used to program a notification function or routineassociated with the analyte monitoring systems.

As described above, in accordance with aspects of the presentdisclosure, alarm or notification routines or functions may beprogrammed, programmable or provided to a user or a patient inconjunction with the use of an analyte monitoring system including ananalyte monitoring device such as, for example, a continuous glucosesensor that provides real time monitoring of glucose levels of thepatient or the user. For example, in one aspect, the frequency of theoccurrence of a notification or alarm associated with a particularcondition (such as, for example, a hypoglycemic condition) may bedetected. The detected occurrence of such notification may be providedto an analyte monitoring system (or retrieved from the storage device ormemory of such monitoring systems) and processed for furthercharacterization, personalization or programming to improve glycemiccontrol resulting in health treatment or therapy management.

In one aspect, programming or configuring an analyte monitoring systemor other physiological condition monitoring device or system to providenotification function and/or alarm features may include monitoringand/or evaluating analyte level information obtained from atranscutaneously positioned analyte sensor, detecting conditionsassociated with the notification or alarm such as, for example, but notlimited to, hypoglycemia, or hyperglycemia, obtaining an in vitro bloodglucose measurement when the notification or alarm is output orasserted, and/or determining the frequency of such notification oralarms asserted or output to the user or the patient. In certainaspects, the in vitro blood glucose measurement results may be used toconfirm the blood glucose level, for example, by comparing the analytelevel associated with the asserted or output alarm notification detectedand analyzed from the analyte sensor to the in vitro blood glucosemeasurements. In certain embodiments, the monitored analyte levelinformation from the transcutaneously positioned in vivo analyte sensormay be used solely to determine whether the alarm or notification istriggered and not subsequently comparing the analyte level with theresults of a contemporaneous in vitro blood glucose measurement. In afurther aspect, the frequency of the alarm or notification assertion(which is related to or triggered by the monitored analyte leveltranscending or crossing a predetermined threshold level or rate ofchange of such monitored analyte level) may be used as a parameter orfactor in determining, modifying or adjusting the alarm parameters.

In certain aspects, the detection of the alarm condition or theunderlying physiological condition associated with the programmednotification includes the detection of such conditions withinapproximately 30 minutes of the occurrence of such conditions. Forexample, multiple data points received from the in vivo analyte sensormay be compared to determine (1) onset of such condition, (2) theoccurrence of such condition, or (3) termination of such condition. Thatis, in one aspect, the alarm or notification occurrence frequency may beevaluated to determine or confirm the presence of the underlying alarmcondition or the onset of the alarm condition.

Accordingly, in aspects of the present disclosure, depending upon thethreshold level setting for the hypoglycemic alarm condition, thepercentage of detection and/or the number of alarms/notificationstriggered may vary. That is, to adjust or modify an alarm setting for anunderlying condition such as the detection of or the onset of ahypoglycemic condition, the frequency of such alarm occurrence over apredetermined time period may be evaluated in conjunction with or inaddition to the assessment of the monitored level rate of changeinformation, and the in vitro blood glucose measurement reading when thealarm is asserted, among others.

In the manner described above, in accordance with aspects of the presentdisclosure, a user, patient or a healthcare provider may customize oradjust the notification functions or alarms programmed or programmablein analyte monitoring devices and systems such as in continuous glucosemonitoring systems such that the customized or adjusted notifications oralarms are more effective in notifying, alerting and/or prompting theuser or the patient to take timely corrective actions based on suchnotifications. For example, if a user or a patient has relatively a hightolerance level for glycemic excursions and does not wish to have thenotifications or alarms associated with glycemic excursions that arerelatively mild (or within a narrower range of variation), based on thefrequency of the alarms or notifications that have occurred during theuse of the analyte monitoring device (for example, during a five dayperiod, or on a bi-weekly or monthly basis, or with each replacement ofthe analyte sensor), the user or the patient may adjust or modify thealarm or notification thresholds or parameters based on, among others,the frequency of the previously triggered notifications and/or alarms,the levels of the thresholds or set (or programmed) levels, and thelike. In this manner, a more effective programming of the notificationor alarm functions/features in conjunction with the monitored analytelevels may be provided to improve glycemic control and healthmanagement.

Accordingly, a method in one aspect includes determining a rate ofoccurrence of a glycemic excursion event, determining a frequency of analarm activation associated with the glycemic excursion event,determining an analyte level associated with the alarm activation, andsetting an alarm parameter based on one or more of the determined rateof occurrence of the glycemic excursion event, the frequency of thealarm activation associated with the glycemic excursion event or thedetermined analyte level.

The glycemic excursion event may include one of hypoglycemic event orhyperglycemic event.

In one aspect, determining the analyte level associated with the alarmactivation may be based, at least in part, on analyte sensor data from atranscutaneous analyte sensor.

The analyte sensor may include a glucose sensor.

Also, determining a rate of occurrence of the glycemic excursion eventmay include monitoring a glucose level for a predetermined time period,detecting the monitored glucose level transcending a predeterminedthreshold glucose level, and determining the rate of occurrence based onthe detected monitored glucose level transcending the predeterminedthreshold glucose level within the predetermined time period.

Moreover, in another aspect, the method may include determining a rateof change of the analyte level associated with the glycemic excursionevent or the alarm activation, or a combination thereof.

In a further aspect, the method may include programming an alarmfunction based on the set alarm parameter.

An apparatus in another aspect of the present disclosure includes aninterface component such as a display unit, a user interface componentincluding input/output units, and the like, one or more processorsoperatively coupled to the interface component; and a memory for storinginstructions which, when executed by the one or more processors, causesthe one or more processors to determine a rate of occurrence of aglycemic excursion event, determine a frequency of an alarm activationassociated with the glycemic excursion event, determine an analyte levelassociated with the alarm activation, and set an alarm parameter basedon one or more of the determined rate of occurrence of the glycemicexcursion event, the frequency of the alarm activation associated withthe glycemic excursion event or the determined analyte level.

Another embodiment may include monitoring an analyte level for apredetermined time period, detecting the monitored analyte levelcrossing a predetermined threshold glucose level, determining afrequency of the detected monitored analyte level crossing thepredetermined threshold analyte level within the predetermined timeperiod, determining an analyte level associated with an alarm thresholdcondition, and updating an alarm parameter related to the monitoredanalyte level based on the determined frequency of the detectedmonitored analyte level crossing the predetermined threshold analytelevel within the predetermined time period.

The detected analyte level crossing the predetermined threshold glucoselevel may be associated with an impending hypoglycemic event or animpending hyperglycemic event.

The analyte level may be a glucose level.

Moreover, an aspect may include determining a rate of change of theanalyte level associated with the detected monitored analyte levelcrossing the predetermined threshold glucose level.

Updating the alarm parameter may include modifying an alarm triggeringthreshold level.

The various processes described above including the processes performedby the processor 204 (FIG. 2) in the software application executionenvironment in the analyte monitoring system 100 (FIG. 1) as well as anyother suitable or similar processing units embodied in the processingand storage unit 307 (FIG. 3) of the primary/secondary receiver unit104/106, and/or the data processing terminal/infusion section 105,including the processes and routines described hereinabove, may beembodied as computer programs developed using an object orientedlanguage that allows the modeling of complex systems with modularobjects to create abstractions that are representative of real world,physical objects and their interrelationships. The software required tocarry out the inventive process, which may be stored in a memory orstorage unit (or similar storage devices in the one or more componentsof the system 100) and executed by the processor, may be developed by aperson of ordinary skill in the art and may include one or more computerprogram products.

Various other modifications and alterations in the structure and methodof operation of the embodiments of the present disclosure will beapparent to those skilled in the art without departing from the scopeand spirit of the present disclosure. Although the present disclosurehas been described in connection with certain embodiments, it should beunderstood that the present disclosure as claimed should not be undulylimited to such embodiments. It is intended that the following claimsdefine the scope of the present disclosure and that structures andmethods within the scope of these claims and their equivalents becovered thereby.

I claim:
 1. A glucose monitoring system, comprising: an on-body unitconfigured to be positioned on a body of a user, the on-body unitcomprising: a glucose sensor, wherein at least a portion of the glucosesensor is configured to be transcutaneously positioned in contact with abodily fluid of the user and detect glucose levels in the bodily fluidof the user; a data processing and transmitter unit coupled with theglucose sensor, the data processing and transmitter unit comprising aBluetooth wireless transmitter and a memory coupled to a processor,wherein the memory stores instructions that, when executed by theprocessor, cause the processor to: store, in the memory of the dataprocessing and transmitter unit, data indicative of the detected glucoselevels over a time period, and cause periodic wireless transmission ofat least a portion of the data indicative of the detected glucose levelsusing the Bluetooth wireless transmitter; a receiver unit, comprising: aBluetooth wireless receiver; a display having a user interface; one ormore processors; and a memory device coupled with the one or moreprocessors, the memory device storing instructions that, when executedby the one or more processors, cause the one or more processors to:receive the at least a portion of the data indicative of the detectedglucose levels using the Bluetooth wireless receiver; cause glucoseinformation based on the at least a portion of the data indicative ofthe detected glucose levels to be displayed on the display; in responseto an input on the user interface, set an alarm threshold and afrequency of an alarm activation associated with one or more glycemicexcursion events; determine an occurrence of the one or more glycemicexcursion events based on the detected glucose levels of the userexceeding the set alarm threshold; cause an alarm to be activated basedon the occurrence of the one or more glycemic excursion events at thefrequency of the alarm activation associated with the one or moreglycemic excursion events while the detected glucose levels exceed thealarm threshold; and cause a notification associated with the one ormore glycemic excursion events to be displayed on the display inresponse to the activation of the alarm; wherein the displayednotification is indicative of the one or more glycemic excursion eventsoccurring in real time.
 2. The glucose monitoring system of claim 1,wherein the one or more glycemic excursion events comprises a lowglucose condition.
 3. The glucose monitoring system of claim 1, whereinthe one or more glycemic excursion events comprises a high glucosecondition.
 4. The glucose monitoring system of claim 1, wherein the oneor more glycemic excursion events comprises the glucose level exceedinga rate of change threshold.
 5. The glucose monitoring system of claim 1,wherein the alarm comprises a vibratory component.
 6. The glucosemonitoring system of claim 1, wherein the alarm comprises an auditorycomponent.
 7. The glucose monitoring system of claim 1, wherein the oneor more processors are configured to set a number of activations of thealarm over a predetermined period of time.
 8. The glucose monitoringsystem of claim 7, wherein the predetermined period of time ends whenthe glucose sensor expires.
 9. The glucose monitoring system of claim 7,wherein the predetermined period of time is a fixed period of time. 10.The glucose monitoring system of claim 7, wherein the predeterminedperiod of time is seven days or more.
 11. The glucose monitoring systemof claim 1, wherein the glucose sensor comprises a plurality ofelectrodes including a working electrode.
 12. The glucose monitoringsystem of claim 1, wherein the data indicative of the detected glucoselevels is calibrated using a factory calibration without furthercalibration from the user.
 13. The glucose monitoring system of claim 1,wherein the data processing and transmitter unit is couplable to theglucose sensor to form the on-body unit.
 14. The glucose monitoringsystem of claim 1, wherein the on-body unit comprises a mount attachableto the user and configured to join the glucose sensor with the dataprocessing and transmitter unit.
 15. The glucose monitoring system ofclaim 1, wherein the data processing and transmitter unit is configuredto encode the data indicative of the detected glucose levels fortransmission to the receiver unit.
 16. The glucose monitoring system ofclaim 1, wherein the on-body unit has a unique ID for communication withthe receiver unit.
 17. The glucose monitoring system of claim 1, whereinthe receiver unit is configured to transmit at least a portion of thedata indicative of the detected glucose levels to a data network forstoring and analyzing the data indicative of the detected glucoselevels.